myFlow.previousMap { previousValue, currentValue -> }

You’re likely looking for a

scan

or

runningReduce

operator

oh i didn't know about runningReduce

zipWithNext?

ok runningReduce was exactly what I was looking for, thank you @wasyl

@Dominaezzz that was my first thought, but it doesn’t look like

zipWithNext

is defined for Flow. But the issue requesting it does have a simple implementation of that operator https://github.com/Kotlin/kotlinx.coroutines/issues/1767

and using flow for byte-by-byte transfer is not ideal either.

I wonder why though

You could compare it to reading a file into memory, byte by byte, instead of in chunks.

yes but what would be better than flow for this use case ? channels ?

Flow of byte buffers maybe.

@nitrog42 Take a look at how Okio works. It’s very elegant and is 100% in Kotlin as of 2018 https://square.github.io/okio/

oh i know about okio 😄